Automotive air conditioning , oil and coolant

1. ENGINE OIL
Coolant and
AC Systems

2. Engine oil provides the following functions:
1. Protect the engine part against wear and corrosion
( Increase engine life time )
2. Cooling the engine parts
( Prevent energy loss and improve engine efficiency )
3. Reduces friction between moving parts and seal space between pistons and cylinders
( Increase engine performance and reduce fuel consumption )
4. Prevent rust and corrosion and remove impurities
( Prevent engine from mechanical damage )
The most important thing to ensure that oil plays its role
is its thickness or viscosity.

3. Engine Oil Viscosity
Dynamic Viscosity
Is a measurement of a fluid’s internal friction or its resistance to
gradual deformation by shear stress or tensile stress. Its units
called centipoise (cP),
Kinematic Viscosity
Is the amount of time that it takes for a specified volume of fluid to flow,
under the force of gravity, through a fixed diameter orifice at a given
temperature. It is usually reported in centistokes (cSt) or mm2/s.

4. Viscosity Index (VI)
How the viscosity of oil varies with
changes in temperature. The higher the
viscosity index, the less the oil’s
viscosity changes with changes in
temperature.

5. Composition Of Engine Oil:

6. Types of Base Oil:
Mineral Oil:
is a byproduct from petroleum distillation. can be
produced to a range of qualities associated with
the oil's refining process and It is a colorless
Semi Synthetic Oil:
Is mineral oil with some proportion and benefits of
Synthetic oil. It provide more effective than mineral
oils but available at low prices than synthetic oils.
Synthetic Oil:
Is contains chemical compounds that are artificially made by adding synthetic molecules, which are not present
in natural crude oils. Scientists designed these synthetic molecules with uniform size and chemistry to reduce
the friction, thus to give the optimum lubricant effect.

7. Synthetic Engine Oil:
 Better protection from mechanical wear.
 Faster lubrication even in low temperature
 Low oil consumption
 Resistance to thermal break-down
 Better engine cleanliness
 Improved efficiency & fuel economy
 High cost
 Oil film is thinner than conventional oil
 Decrease oil sealing effect

8. Engine Oil Additives:
Impart new characteristics to the base oil, or improve existing characteristics, enabling it to function in a
desired manner when used to lubricate an engine.

9. Oil Ratings :

10. Engine Oil Rating :

11. Engine Oil Viscosity Classification

12. Engine Oil Rating :
The API performance or service classification. Oil can be classified as energy-
conserving oils . These are designed to reduce friction, which in turn reduces fuel
consumption.
GASOLINE ENGINE RATINGS:
In gasoline engine ratings, the letter S indicate spark ignition engines. The rating system is open ended so
that newer, improved ratings can be readily added as necessary

13. DIESEL ENGINERATINGS:
Diesel classifications begin with the letter C, which stands for
commercial, but can also indicate compression ignition or diesel
engines.

14. The (ACEA) rates the oil according to the following:
The European Automobile Manufacturers' Association is an organization that represents the 15 most
important European motor vehicle manufacturers. According to their statement, ACEA is an advocate for
the automobile industry in Europe, representing manufacturers of passenger cars, vans, trucks and buses
with production sites in the EU.
Among many other activities ACEA defines specifications for engine oils so called ACEA Oil Sequences.
The sequences are usually updated every few years to include the latest developments in engine and
lubricant technology. ACEA itself does not approve the oils, they set the standards and oil
manufacturer's may make performance claims for their products if those satisfy the relevant requirements.

15. The (ACEA) rates the oil according to the following:
low levels of sulfated ash, phosphorous, and sulfur,

16. Low SAPS : Low levels of sulfated ash, phosphorous, and sulfur
HTHS: High temperature/high shear rate viscosity.
C ratings are catalytic converter compatible oils and include:
C1: basicallyA5/B5 oil with low SAPS, low HTHS
C2: A5/B5 with low HTHS and mid-level SAPS
C3: A5/B5 with high HTHS and mid-level SAPS
C4: low SAPS; high HTHS
ACEA Technical Performance level:

17. VISUAL CHECKS:
Engine Oil Level and Condition:
Carry out a visual inspection of the oil level with
the dipstick:
1. Be sure that the vehicle stay on flat road.
2. Be sure the engine is cold before you check the oil.
3. Pull out the dip stick and wipe it off on a clean.
4. Insert the stick back into the pipe.
5. Pull the dipstick out again and look at the film of oil
on the end of the stick.

18. Oil Condition:
Dark brown or black indicate contamination
which is normal but only if the oil is also thick.
because dark color by itself isn't indicator of a
problem in engine as some additives for
cleaning cause engine oil to darken quickly.
• Thin & dark oil with burned smell
indicate engine internal problem
• Thick & dark oil usually indicates dirt or
contaminants.
• Milky, foamy, or cream-colored oil
can be indicative water contamination.

19. BASIC SERVICES
BRAKE FLUID

20. Brake fluid is made from a combination of various types of glycol, a non-
petroleum-based fluid.
Brake fluid is a polyalkylene-glycol-ether mixture, called polyglycol for short.
All polyglycol brake fluid is clear to amber in color.
All automotive brake fluid must meet Federal Motor Vehicle Safety Standard.
The Society of Automotive Engineers (SAE) and the Department of
Transportation (DOT) have established brake fluid specification standards.
Brake Fluid:

21. DOT 3:
- The color of DOT 3 ranges from clear to light amber.
- It absorbs moisture and it can absorb 2% of its volume in water per year.
- DOT 3 must be used from a sealed container.
- Very strong solvent and can remove paint
DOT 4:
- The color of DOT 4 ranges from clear to light amber.
- The brake fluid is formulated for use by all vehicles.
- It is commonly called low moisture absorption (LMA) because it does not absorb water as fast as DOT 3
- The cost of DOT 4 is approximately double the cost of DOT 3.
DOT 5:
- The color of DOT 5 is purple .
- This type is commonly called silicone brake fluid.
- It does not absorb water, it is called non hygroscopic.
DOT 5.1:
- The fluid is a non-silicone-based polyglycol fluid that is clear to amber in color.
- This severe duty fluid has boiling point over 500°F,(260°C) equal to boiling point of silicone-based fluid.

22. Moisture is absorbed by the brake fluid
in the brake
through microscopic seams
system and around seals.
Moisture can cause a spongy brake pedal because the increased
concentration of water within the fluid boils at lower temperatures
and can result in vapor lock.
DOT 5 fluid does not mix with and should not be used with DOT 3 or DOT 4 brake fluid.
If any mineral oil such as engine oil, (ATF), or power steering
fluid gets into the brake fluid, the rubber seals will swell and
cause damage to the entire braking system.
Brake Fluid compatibility chart

23. LHM (Liquide Hydraulic Mineral) Brake Fluid
LHM Fluid is a specially formulated mineral based hydraulic and brake fluid, it has been especially
developed for application in brake systems, levelling and hydraulic controlled clutches
LHM Fluid is manufactured from a specialized mineral oil and selected additives to produce a
hydraulic and brake fluid with a very high viscosity index.
Benefits:
• Suitable for use in systems with pressure up to and in excess of 150bar
• No water absorbing
• Excellent lubricating properties.
• Very good protection against corrosion.
• High compatibility with all types of seals and gaskets.
• High chemical stability even in the most severe conditions of thermal stress.

24. COOLING SYSTEM

25. Engine coolant:
Engine coolant is a mixture of water and antifreeze.
Water alone has a boiling point of 212°F (100°C )
and a freezing point of 32°F (0°C ) at sea level.
A mixture of 70 percent antifreeze and 30 percent water wi
ll raise the boiling point of the mixture to 276 ° F ( 136 ° C
) under 15 psi of pressure and lower the freezing point to
– 84 ° F ( − 64 ° C ).
Normally, the recommended mixture is:
50% Pure Water
44% to 47% Antifreeze
6% to 3% Additives (anti – rust and cleaners)

26. Engine coolant Types:
Inorganic Acid Technology (IAT)
This was once the most commonly used antifreeze. It uses Ethylene glycol is green in color, and provides
good protection regardless of climate but it is poisonous. IAT coolant is not compatible with newer long-life
coolants.
Organic acid technology (OAT)
This coolant is also environmentally friendly and contains zero phosphates or silicones. This orange
coolant is often referred to by a brand name “DEX-COOL” and is used in most late model.
Hybrid organic acid technology (HOAT)
This is similar to OAT coolant but has additives that make the coolant less abrasive to water pumps. This
type of coolant is used by some modern vehicles and is not compatible with IAT or OAT coolants.

27. Engine coolant Colors:

28. History
• The Packard Motor Car Company was the first automobile
manufacturer to build air conditioners into its cars, beginning
in late 1939 and Then in 1953 Chrysler Imperial was the first
production car to actually have automobile air conditioning.
Theory
• Air conditioning system in a vehicle is a part of HVAC system
which allows adjusting of air temperature, humidity, and
direction.
• The automotive air-con system must control four (4)
conditions within the vehicle interior:
• It must [ 1) cool the air 2) circulate the air 3) purify the air
4) dehumidify the air ]

29. How does heat get inside
a vehicle?
• When a car is driven or parked in
the sun, heat enters the vehicle
from many sources: Ambient air,
Sunlight, Engine heat, Road heat,
Exhaust heat…
• In a high ambient temperature
situation (e.g. on a 37 o
C day), the
interior of a vehicle left standing
in the sun with windows closed
could reach 65-70 o
C .

30. Refrigerants in Automotive Air Conditioning
Systems
After the R12 refrigerant (Freon) used in A/C units was
blamed for depleting the ozone layer, automakers were
required to switch to the less harmful R134a refrigerant
by 1995.
Note: R134a lives for around 13 years in the atmosphere
before breaking down
First vehicles with new refrigerant HFO-1234yf
developed to meet EU directives, which demand a
refrigerant with a GWP of less than 150, appears on the
market in 2012.
HFO1234yf is a new refrigerant that breaks up in around
11 days. It was developed to meet EU directives.
R134a probably will not disappear till 2025 year.
R12
(in use till 1990)
R134-a
(in use 1990-2016)
1234yf
(in use from 2012)
Chemical name (CFC)
ChloroFluoroCarbon
(HFC)
HydroFluoroCarbon
HFO
HydroFluoroOlefin
Ozone depleting
potential (1=max) 1.0 0 0
Global warming
potential (GWP) 2400 1400 4
Boiling point on
atmospheric pressure -29.6 o
C -26.3 o
C -29 o
C
Flammability Risk No No Low-Mid
Toxicity Low Low Low

31. How Automotive Air Conditioning Works
The basic components found in a vehicle air conditioner are the
1. compressor
2. Condenser
3. Evaporator
4. Receiver drier
5. Expansion valve.
To understand the operation of the five major components of an
automotive A/C system remember that the air-conditioning unit is
divided into two sides:
-The high side of the system refers to the parts that are under high
pressure and high temperature.
-The low side of the system referrers to low pressure components that
are larger in diameter as far as
the hoses and tubing and these components will be ice cold to the
touch.

32. scroll type
Rotary vane type
Piston-driven
Compressor
The work horse of the air conditioning
system, powered by a drive belt connected
to the crankshaft of the engine.
When the air con system is turned on, the
compressor pumps refrigerant vapor under
high pressure to the condenser.
There are 3 types of auto A/C compressors

33. Condenser
function is to act as a heat exchanger and
allow heat to flow from the hot refrigerant to
the cooler outside air.
change the high-pressure refrigerant vapor to a
liquid. It is mounted in front of the engine's
radiator, and it looks very similar to a radiator.
The vapor is condensed to a liquid because the
heat is removed from the condenser by air
flowing through the condenser on the outside.

34. Expansion Valve
its job is to control the amount of
refrigerant entering the
evaporator.
Expansion valve removes pressure
from the liquid refrigerant.
The expansion valve serves as a
“dividing line” between the high and
low pressure sections of the system.

35. Evaporator
looks similar to a car radiator. It has
tubes and fins and is usually
mounted inside the passenger
compartment.
As the cold low-pressure refrigerant is
passed into the evaporator, it vaporizes and
absorbs heat from the air which comes from
the passenger compartment.
The blower fan inside the passenger
compartment pushes air over the outside of
the evaporator, so cold air is circulated
inside the car.